And just like that, the defensive talent pool in Baltimore becomes even shallower.

Already thin at safety following the offseason departures of Ed Reed and Bernard Pollard, the Ravens' depth took another hit Monday when Christian Thompson was suspended by the NFL for violating the league's substance abuse policy.

As a first-time offender, Thompson will miss the first four games of the 2013 season without pay. He will still be eligible to participate in all offseason activities, practices, and preseason games.

“We have been aware of this situation for some time,” General Manager Ozzie Newsome said in a release.

Drafted in the fourth round last year out of South Carolina State University, Thompson saw action exclusively on special teams. Though he appeared in seven games during the Ravens' Super Bowl-winning season, he failed to record a tackle.